This invention relates to surgical instruments and more particularly to an improved surgical retractor.
Surgical regractors are well known and have been in widespread use for many years. While they are very useful and necessary in maintaining the body open during various types of major surgery, the present retractors have the disadvantage that, on occasion, their use may result in inadvertant damage to the internal organs of the patient by moving during the procedure and/or to accidental and dangerous disruption of the surgical procedure by collapsing and falling out of the wound if the patient "bucks" under general anaesthesia. Simple respirations can also cause disruption of the position of the instrument especially in the flank. This sudden closure of the wound often occurs at a critical time during the operative procedure which may have severe consequences.
As shown in U.S. Pat. Nos. 1,311,313 which issued July 29, 1919 to Brix and 2,850,008 which issued Sept. 2, 1958 to Resch, some of the known retractors do not have any positive locking means and rely only on the sliding arm being slightly askew to maintain it in the desired position. This is a very dangerous situation because during surgery the retractor is under a very considerable load and the patient is constantly moving (i.e. respirations) and if the retractor is accidentally jarred or levered, it could immediately release causing irreparable damage during a crucial or delicate part of the operation. U.S. Pat. Nos. 1,706,500 which issued Mar. 26, 1929 to Smith and 1,963,173 which issued June 19, 1934 to Morin show attempts to overcome this problem using ratchet means and while this is an improvement it still is not satisfactory. Another attempt to overcome this problem is to provide a retractor with a screw lock, but this similarly is not sufficiently positive, is awkward to use and may come free during the procedure and get lost in the peritoneal cavity of retroperitoneal space. Another attempted solution which has not been entirely satisfactory is shown in U.S. Pat. No. 3,227,156 which issued Jan. 4, 1966 to Gauthier.
As shown in U.S. Pat. No. 2,450,194 which issued Sept. 28, 1948 to Glaser ratchet retractors may also have the disadvantage that too much force may be applied to the body opening resulting in permanent damage to the surrounding area. Mechanically assisting the forcible opening of the body opening has even been known to result in the breaking of ribs and damaging of organs. It is normally desirable to spread the wound open as far as the incision will permit without causing any damage. Therefore, it is essential that the surgeon be able to accurately feel the force being applied by the retractor arms during extension and also be able to quickly and conveniently positively secure the locking means when the desired position is reached.
Another important source of potential retractor damage to the body arises if the retractor cross member is not positioned against the patient's abdomen or flank during use. While this problem does not normally occur during abdominal surgery, it presently is an accepted problem during kidney surgery. In standard renal surgical procedures, the surgeon stands at the patient's back and leans over and in fact touches the retractor cross member as the arms extend rearwardly from the incision. If the surgeon's body accidentally exerts any downward force on the retractor cross member, it has the effect of pivoting the blades of the retractor upwards in the wound resulting in possible damage to major blood vessels or internal viscera such as the spleen, liver, lungs, etc. Occasionally this results in the retractor pivoting sufficiently to be twisted right out of the wound causing it to close suddenly. To make things worse, this normally happens during a critical part of the operation when the surgeon is concentrating on what he is doing and may lean over a little further than normal or may lean from fatigue.